/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 1997, 1998, 1999, 2000, 2001 by Ralf Baechle
 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
 * Copyright (C) 2001 MIPS Technologies, Inc.
 */
#ifndef _ASM_HARDIRQ_H
#define _ASM_HARDIRQ_H

#include <linux/config.h>
#include <linux/threads.h>
#include <linux/irq.h>

typedef struct {
	unsigned int __softirq_pending;
	unsigned int __syscall_count;
	struct task_struct * __ksoftirqd_task;	/* waitqueue is too large */
} ____cacheline_aligned irq_cpustat_t;

#include <linux/irq_cpustat.h>	/* Standard mappings for irq_cpustat_t above */

/*
 * We put the hardirq and softirq counter into the preemption
 * counter. The bitmask has the following meaning:
 *
 * - bits 0-7 are the preemption count (max preemption depth: 256)
 * - bits 8-15 are the softirq count (max # of softirqs: 256)
 * - bits 16-23 are the hardirq count (max # of hardirqs: 256)
 *
 * - ( bit 26 is the PREEMPT_ACTIVE flag. )
 *
 * PREEMPT_MASK: 0x000000ff
 * SOFTIRQ_MASK: 0x0000ff00
 * HARDIRQ_MASK: 0x00ff0000
 */

#define PREEMPT_BITS	8
#define SOFTIRQ_BITS	8
#define HARDIRQ_BITS	8

#define PREEMPT_SHIFT	0
#define SOFTIRQ_SHIFT	(PREEMPT_SHIFT + PREEMPT_BITS)
#define HARDIRQ_SHIFT	(SOFTIRQ_SHIFT + SOFTIRQ_BITS)

#define __MASK(x)	((1UL << (x))-1)

#define PREEMPT_MASK	(__MASK(PREEMPT_BITS) << PREEMPT_SHIFT)
#define HARDIRQ_MASK	(__MASK(HARDIRQ_BITS) << HARDIRQ_SHIFT)
#define SOFTIRQ_MASK	(__MASK(SOFTIRQ_BITS) << SOFTIRQ_SHIFT)

#define hardirq_count()	(preempt_count() & HARDIRQ_MASK)
#define softirq_count()	(preempt_count() & SOFTIRQ_MASK)
#define irq_count()	(preempt_count() & (HARDIRQ_MASK | SOFTIRQ_MASK))

#define PREEMPT_OFFSET	(1UL << PREEMPT_SHIFT)
#define SOFTIRQ_OFFSET	(1UL << SOFTIRQ_SHIFT)
#define HARDIRQ_OFFSET	(1UL << HARDIRQ_SHIFT)

/*
 * The hardirq mask has to be large enough to have
 * space for potentially all IRQ sources in the system
 * nesting on a single CPU:
 */
#if (1 << HARDIRQ_BITS) < NR_IRQS
# error HARDIRQ_BITS is too low!
#endif

/*
 * Are we doing bottom half or hardware interrupt processing?
 * Are we in a softirq context? Interrupt context?
 */
#define in_irq()		(hardirq_count())
#define in_softirq()		(softirq_count())
#define in_interrupt()		(irq_count())

#define hardirq_trylock()	(!in_interrupt())
#define hardirq_endlock()	do { } while (0)

#define irq_enter()		(preempt_count() += HARDIRQ_OFFSET)

#if CONFIG_PREEMPT
# define in_atomic()	(preempt_count() != kernel_locked())
# define IRQ_EXIT_OFFSET (HARDIRQ_OFFSET-1)
#else
# define in_atomic()	(preempt_count() != 0)
# define IRQ_EXIT_OFFSET HARDIRQ_OFFSET
#endif
#define irq_exit()                                                     \
do {                                                                   \
	preempt_count() -= IRQ_EXIT_OFFSET;                     \
	if (!in_interrupt() && softirq_pending(smp_processor_id())) \
		do_softirq();                                   \
	preempt_enable_no_resched();                            \
} while (0)

#ifndef CONFIG_SMP
# define synchronize_irq(irq)	barrier()
#else
  extern void synchronize_irq(unsigned int irq);
#endif /* CONFIG_SMP */

#endif /* _ASM_HARDIRQ_H */
